Problem: ${12 \div \dfrac{2}{5} =}$
Explanation: ${12} \div \dfrac{2}{5}} ={\dfrac{12}{1}} \div \dfrac{2}{5}} $ $~~~~~~~{\gray{\text{Rewrite 12 as }\dfrac{12}{1}.}} $ $\phantom{8 \div \dfrac{2}{3}}} ={\dfrac{12}{1}} \times \dfrac{5}{2}}$ $ ~~~~~~{\gray{\text{Multiply by reciprocal of }\dfrac25.}} $ $\phantom{8 \div \dfrac{2}{3}}} ={\dfrac{{12}\timesD5}{1\timesD2}} $ $~~~~~~~{\gray{\text{Multiply. }}} $ $\phantom{12 \div \dfrac{2}{3}}} ={\dfrac{60}{2}} $ $~~~~~~~{\gray{\text{Simplify. }}} $ $\phantom{12 \div \dfrac{2}{3}}} =30 $ ${12 \div \dfrac{2}{5} =30}$